FIXED ASSETS

Fixed assets, net summarized by major category, consist of the following (in thousands):



	December 31,
	2014			2013
Machinery and laboratory equipment	$	29,697		$	19,570
Computer equipment and software	3,754			2,476
Office furniture and equipment	1,001			441
Leasehold improvements	26,350			24,852
Construction in progress	19,944			13,419
Total	80,746			60,758
Less: accumulated depreciation	(20,114		)	(12,576		)
Fixed assets, net	$	60,632		$	48,182

Depreciation expense for the years ended December 31, 2014, 2013 and 2012 was $9.3 million, $3.7 million and $3.6 million, respectively. During the years ended December 31, 2014, 2013 and 2012, the Company capitalized interest of $0.4 million, $1.1 million and $2.0 million, respectively. The balance of construction in progress at December 31, 2014 relates largely to the construction of a new manufacturing facility in the United Kingdom and a new fill line for EXPAREL at the Company’s Science Center Campus in San Diego, California.